Memory devices are typically provided as internal, semiconductor, integrated circuits in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), flash memory, phase change random access memory (PCRAM), spin torque transfer random access memory (STTRAM), resistive random access memory (RRAM), magnetoresistive random access memory (MRAM; also referred to as magnetic random access memory), conductive-bridging random access memory (CBRAM), among others.
Memory devices are utilized as non-volatile memory for a wide range of electronic applications in need of high memory densities, high reliability, and low power consumption. Non-volatile memory may be used in a personal computer, a portable memory stick, a solid state drive (SSD), a personal digital assistant (PDA), a digital camera, a cellular telephone, a portable music player (e.g., MP3 player), a movie player, and other electronic devices, among others. Program code and system data, such as a basic input/output system (BIOS), are typically stored in non-volatile memory devices.
Many memory devices, such as RRAM, PCRAM, MRAM, STTRAM and CBRAM, for example, can include arrays of memory cells organized in a two-terminal cross-point architecture, for instance. In various instances, such memory cells may fail (e.g., become unusable). As an example, a failed memory cell may create a short between the word line and bit line associated with the cell by becoming stuck in a closed state (e.g., by becoming irreversibly stuck in a low resistance state). The word line-bit line short can prevent the word line and bit line from being driven to different potentials, which can prevent the ability to operate (e.g., program, read, erase, etc.) cells coupled to the particular word line and/or bit line. Furthermore, depending on the operating scheme associated with the memory device, the short can also prevent cells coupled to adjacent word lines and/or bit lines from being operated properly.
Some previous approaches compensate for a failed memory cell by providing redundant word lines and bit lines that can be used to replace the word lines and bits lines made unusable by a failed memory cell. For instance, the addresses of the unusable word lines and bit lines can be mapped to new addresses in redundant memory. However, providing redundant memory capacity has drawbacks such as increasing the die size associated with the memory device and can slow operation of the memory device, among other drawbacks.